Malicious PDF — malware analysis report

Static analysis result for SHA-256 31a4c09b34012bf1…

MALICIOUS

PDF

80.5 KB Created: 2021-09-15 10:48:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3d8cbb107a429695249303220b1ffe07 SHA-1: f07ed0358220cea3cc919364a1aa94d90e9a6f11 SHA-256: 31a4c09b34012bf12c9a7dc94dd00ff57f0cf31c7c2e2e9f8eee1894e755f552
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of embedded URLs, many pointing to compromised websites or disposable domains, suggesting a link farm designed for SEO manipulation or to distribute further malicious content. No scripts were extracted from this sample.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://varvshistoriska.com/file/82452887314.pdf
    • http://www.mondzorgvesa-voorschoten.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16134c4c1b31fa---ruzukoguzimodi.pdf
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/2ehiipru13v2mqs0pqu24ce5r1/22979839766.pdf
    • http://aasghsflqsae.handylover.com/upload/files/guzidinifirizar.pdf
    • https://hazeloyun.com/calisma2/files/uploads/xaraboduratabiniwanujone.pdf
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/161345577d9a38---7453500442.pdf
    • http://eternaseguros.net/files/files/madajulomunapevabu.pdf
    • https://associazionemusicaviva.it/uploads/file/bifibozaniwuperedara.pdf
    • http://blossomtour.net/FileData/ckfinder/files/20210910_F547C8726463AA17.pdf
    • https://dukeofmarshall.com/ckfinder/userfiles/files/tovorogaf.pdf
    • https://www.tcf.gov.tr/ckfinder/userfiles/files/28225129508.pdf
    • http://zamokugrofa.sk/admin/fckeditor/file/39588251913.pdf
    • http://livestreaming.group/wp-content/plugins/super-forms/uploads/php/files/0t9odbrganf5lmj149756hbgr6srf3d1/35831936658.pdf
    • http://luxlustry.ru/img/upload/84674871880.pdf
    • http://hvpeds.com/upload/contents/file/wuzifuzabef.pdf
    • https://sanipro.ma/app/webroot/uploaderfiles/52640573524.pdf
    • http://residenceraffaellotorino.com/userfiles/files/29029063984.pdf
    • http://citescolairedeledit.com/include/file/zobigaxadufiwaxud.pdf
    • http://majorpropertygroup.com/userfiles/files/viwegimowafixitekapegege.pdf
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614047055af4f---tuwafufutilif.pdf
    • https://invision.buzyhub.com/files/petoronufa.pdf
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614174b3caa9c---6363841461.pdf
    • https://datenglagi.com/contents/files/fonamefulunoxusokap.pdf
    • http://sake-tori.com/images/library/File/xelofotezizar.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=yahoo+weer+app+android
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d8e0.bin
d17d17fd18548b2ccd93ed4db35d6c7bd69d83be88ea89a8f6920325322b7866
pdf-font-stream PDF embedded font (sfnt) at offset 0xD8E0 17404 bytes
font_01_sfnt_off000105b3.bin
c70c5e20541276d189ab4a7ab16abc3540b09089a23a6fe0aa0bb350f48fff32
pdf-font-stream PDF embedded font (sfnt) at offset 0x105B3 10244 bytes
font_02_sfnt_off00011c9f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11C9F 16792 bytes